<template>
    <div class="s-draw">
        <canvas id="s-draw" :width="contentWidth" :height="contentHeight"></canvas>
    </div>
</template>
<script>
export default {
    name: 'SIdentify',
    props: {
        identifyCode: {
            type: String,
            default: '1234',
        },
        fontSizeMin: {
            type: Number,
            default: 25,
        },
        fontSizeMax: {
            type: Number,
            default: 30,
        },
        backgroundColorMin: {
            type: Number,
            default: 255,
        },
        backgroundColorMax: {
            type: Number,
            default: 255,
        },
        colorMin: {
            type: Number,
            default: 0,
        },
        colorMax: {
            type: Number,
            default: 160,
        },
        lineColorMin: {
            type: Number,
            default: 100,
        },
        lineColorMax: {
            type: Number,
            default: 255,
        },
        dotColorMin: {
            type: Number,
            default: 0,
        },
        dotColorMax: {
            type: Number,
            default: 255,
        },
        contentWidth: {
            type: Number,
            default: 132,
        },
        contentHeight: {
            type: Number,
            default: 31,
        },
    },
    methods: {
        // 生成一个随机数
        randomNum(min, max) {
            return Math.floor(Math.random() * (max - min) + min)
        },
        // 生成一个随机的颜色
        randomColor(min, max) {
            let r = this.randomNum(min, max)
            let g = this.randomNum(min, max)
            let b = this.randomNum(min, max)
            return 'rgb(' + r + ',' + g + ',' + b + ')'
            // return "#15B9E0"
        },
        drawPic() {
            let canvas = document.getElementById('s-draw')
            let ctx = canvas.getContext('2d')
            ctx.textBaseline = 'bottom'
            // 绘制背景
            // ctx.fillStyle = 'rgb(16, 60, 134)'
            ctx.fillStyle = 'rgb(213, 243, 220)'
            ctx.fillRect(0, 0, this.contentWidth, this.contentHeight)
            // 绘制文字
            for (let i = 0; i < this.identifyCode.length; i++) {
                this.drawText(ctx, this.identifyCode[i], i)
            }
            // this.drawLine(ctx)
            // this.drawDot(ctx)
        },
        drawText(ctx, txt, i) {
            ctx.fillStyle = this.randomColor(this.colorMin, this.colorMax)
            ctx.font = this.randomNum(this.fontSizeMin, this.fontSizeMax) + 'px SimHei'
            let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1))
            let y = this.randomNum(this.fontSizeMax, this.contentHeight - 5)
            var deg = this.randomNum(-45, 45)
            // 修改坐标原点和旋转角度
            ctx.translate(x, y)
            ctx.rotate((deg * Math.PI) / 180)
            ctx.fillText(txt, 0, 0)
            // 恢复坐标原点和旋转角度
            ctx.rotate((-deg * Math.PI) / 180)
            ctx.translate(-x, -y)
        },
    },
    watch: {
        identifyCode() {
            this.drawPic()
        },
    },
    mounted() {
        this.drawPic()
    },
}
</script>
<style scoped></style>
